The shoulder is a ball-and-socket joint, surrounded by connective tissues known as the shoulder capsule. Frozen shoulder happens when the shoulder capsule becomes thick and tight, making it difficult for the shoulder to move normally.
Frozen shoulder, also known as adhesive capsulitis, results in loss of movement and pain or stiffness in one or both shoulder joints. This pain and loss of movement can affect daily activities.
The most obvious symptom of frozen shoulder is dull pain in your shoulder and the shoulder muscles that wrap around the top of the arm. The pain may worsen at night, making it difficult for you to sleep. The tightness of the shoulder capsule may also limit your range of movement.
Frozen shoulder typically resolves over 2 – 3 years, in 3 distinct stages. Each stage can last several months.
In the first stage, you may experience:
This stage may last from 6 weeks – 9 months.
In the second stage, you may experience less pain with any shoulder movement. However, you will still have stiffness and limited shoulder movement.
This stage may last from 4 – 6 months.
In the last stage, you are likely to experience the least pain with any shoulder movement, and improved shoulder movement. However, pain may recur from time to time.
This stage may last from 6 months – 2 years.
The exact cause of frozen shoulder is not fully understood.
In some cases, inflammation causes parts of the shoulder capsule to become thickened and scarred. This reduces the volume of the shoulder joint, limiting the shoulder's ability to move and causing the shoulder to freeze.
You may have a higher risk of having frozen shoulder if:
Complications of frozen shoulder include:
If you were recently injured, you can prevent a frozen shoulder by maintaining the mobility of your shoulder joint while recovering.